Transformer.



T. E. BARNUM.

TRANSFORMER.

APPLIOATION FILED MAY 15, 1911.

Patented June 2, 1914.

2 SHEETS-SHEET 1. I

V j 1272077205 K302 21072.

T. E. BARNUM TRANSFORMER. APPLICATION FILED MAY 15, 1911.

Patented June 2, 1914.

' 2 SHEETS-SHEET 2.

STATES PArE-N omica.

moms E.- BARNUM, or xnwauxnn, WISCONSIN, assrenon T0 was. CUTLEB- menuse. 00., or MILWAUKEE, WISCONSIN, A conronazrron or WIS- OONSIN. r

4 mmnssonmang Patented June 2. 191a.

Application filed May 1-5, 1911. serial No. 027,366.

To all whom it may concern:

. Be it known that I, THOMAS E. 'BARNUM, a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented new and useful Improvements in Transformers, of

which the following is a full, clear, concise,

and exact description, reference being had to the accompanying drawing,forming a part of this specification.

My invention relates to improvements in adjustable transformers.

My invention is particularly applicable to transformers for are lamps,but is not limited to this particular application.

One of the objects of my invention is to provide a device of simple,compact-and durable construction.

A further object of my invention is .to provide a device which willenable voltage regulation between predetermined limits in very minute.degrees, I

Variousother objects and advantages of my invention willbe hereinafterset forth.

In order to disclose the nature and characteristic features of myinvention I shall describe the embodiment thereof illustrated in theaccompanying drawings.

It should be understood that my invention is not limited to the specificembodiment thereof illustrated in the accompanying drawings, but issusceptible of various modi: fications.

In the accompanying drawings: Figure 1 is a top plan View of the device.Fig. 2 isa side elevation of Fi 1 Fig. 3 is a sectional view taken online 3-3 Fig. 1. Fig.

4 is a' top plan view of the transformer frame and movable plu Fig. 5 isa sectional view of the movable plug on the'line 5-5 Fig. 3. Fig, 6 is adiagrammatic view showing the device connected to a lamp circuit. a

The structure illustrated includes a base or supporting member 1 havinglugs or ears 2 formed thereon for facilitating its attach-' ment to asuitable supporting device. The

member 1 is preferably made n the form of. a hollow box as illustratedof a rectangular form. The sides and bottom of the member 1 are rovidedwith apertures 3 suitably arrange therein for ventilating purposes. Ateach corner of the supporting member 1 is provided a perforated lug orear 4.

Superimposed upon the open end of the has its corners beveled asillustrated, Fig. 4,

for a purpose hereinafter set forth. Superimposed upon the laminatedframe 5 1s a box-like member 11 provided at its corners with perforatedlugs or ears 12. The member 11 is secured to the member 1 by bolts 13passing through the corner lugs of both members, the frame 5 beinclamped between the two memii The purpose of beveling the corners of thelaminated member.5 is to provide clearance for the bolts 13, and at thesame time utilize sa1d 'bolts for engagement with the beveled edges ofthe frame 5' to retain the same in position relative to the members 1and 11..

The box-like. member 11 is provided with a removable cover 16 preferablyheld in place by screws 17 at the corners thereof which thread intosuitable blocks 18 provided at 7 thus firmlyers 1 and 11.

the'corners'of the member 11. As illustrated in Fig. '1 the cover 16 isprovided. with aplurallt-y of apertures 19 forventilating pure poses.

Within the device described are located two transformer coils 20 and 21best illustrated in Fig. 4. These coils may be' of any suitableconstruction. They are mounted upon the laminated frame 5. More specifivcally they are wound around or fitted on to the central portion 10 ofthe laminated frame 5, said portion 10 forming a core therefor. Thesecoils are disposed at 0pleo posite ends of the member 10, or in othervwords at opposite-ends of the openings 8 and 9 through said frame 5leaving spaces between the same into which are fitted two verticallydisposed tubular members 22 and 23. These members hold the coils inspaced 7 relation, and saidcoils are further secured in place by woodenwedges 20" and 21*, best illustrated in Fig. 3 interposed between thesame and the member 10 on which they are supported. The tubes 22 and 23are preferab y rectangular in form and composed of anon-conclucting"material preferably fiber or leatheroid. These tubes arepreferably supported at their .upper ends between two parallel bars 24extending across the'box member 11 and resting u on and secured to lugs25 within' said mem -er. Only one of these bars is illustrated, the samebein shown in Fig. 3. The tubes. are also preerably secured in lace bybolts connecting their lower en s to the sides of the supporting -Thiswill readily .trated by which member 1 as illustrated in Flg. 3.

Arranged to move longitudinally in each of the tubes 22 and 23 is amagnetic plug member 31 preferably formed of laminations 32 confinedbetween outside plates 33 and 34, the laminations and said plates beingsecured together by suitable rivets 35 and 36. The two plug members 31are connected to a cross head 39, said cross head preferably having itsends set into said members 31 and secured thereto by the rivets 36. Thecross head 39 works in vertical slots provided in adjacent sides of thetubular members 22'and 23. For a purpose hereinafter set forth it isdesired to raise and lower the plug members in the tubes, and to providefor this movement I thread into the cross head 39 a screw threadedvertically disposed shaft 40 revolubly mounted in a suitable bearing 41provided in the top 16. Secured to the end of the shaft 40 exterior tothe top 1- is a handle 42. The handle 42 provides means for rotating theshaft 40, and through its screw threaded engagement with the cross head39 to raise and lower said cross head. In practice I have found thatthere is a tendency of the plug members 31 to vibrate laterally, and soto prevent undue vibration of these members I have provlded each ofcoils 20 and 21 the same with leaf springs 43 adapted to bear against asideof the tube in which it works, to steady the same.

Before proceeding. further I shall describe the purposes and functionsof the above structure in connection with Fig. 6. As before stated inthe arrangement shown in Fig. 6 the device is used for regulating an arclamp circuit. Thelamp is schematically illustrated as provided withcarbons 44 and 45 and as being connected by con-' ductors 46 and 47respectively to the terminals of the transformer coil 21. The two areconnected in series and are provided with leads 48 and 49 for connectingthe same across a suitable single tentials, vI have provided phasealternating current circuit. The coil 20 is the primary coil, and thecoil-21 is the secondary coil. For providing for connection of thedevice to circuits of difierent poa tap 50 from the coil 20. This tapmay be arranged to cut out tween of the magnetic flux away force shuntedaway thereby insuring a any predetermined number of turns of the coil 20and thus be used where connection is made to a circuit of a lowerpotential than that. for which the whole coil is designed. By relativevariation of the number of turns in each coil any predetermined inducedpotential across the lines 46 and 47 connecting the are light to thecoil 21 may be obtained. be understood by those from the connectionsillusthe coils are connected to produce an auto transformer. It willfurther be understood by those skilled in the art that variations in thenumber .of lines of force passing through the core of the secondary coil21 will cause variations in the induced voltage in the coil. That istoasay by decreasing the number of lines of force through therore bf thecoil 21, the induced skilled in the art otential across said coil may bedecreased and that by increasing the number of lines of force passingtherethrough the induced potential across said. coil may be increased.It is for the purpose of thus controlling the number of lines of forcepassing through the core of the coil 21 that I have provided theadjustable plugs 31. These plugs when inserted fill or partially fill,according to the degree of insertion thereof, the air gap bethe centralportion 10 of the frame 5 and the outside portions mally takes the pathindicated by the light dotted linesto the shorter path indicated by thedarker dotted lines. the insertion of the plugs shunts a portion fromthe core of the coil 21 and in consequence for the reason thereof, anddivert a portion of the magnetic flux which nor In other words abovestated decreases the voltage induced in the said coil. The number oflines of force thus diverted and consequent decreased potential acrossthe terminals of the winding 21 depends upon the degree of insertlon ofthe plugs .31.

Obviously the insertion of-these plugs the number of lines of from thecoil 21. Here greater the degree of the greater will be those skilled inthe art as the secondary current increaseswhen the carbons are movedtogether, the secondary voltagedecreases;

that the screw threaded v and as the current decreases by virtue of thecarbons burning away, the voltage increases,

good light at all times. Again referrmg to the mechanical structure itwill be observed from Figs. 1, 2 and 4 that the ingoing leads 48, 4.9and enter the casing at one side thereof while the outgoing leads 46 and47 leave the casing at the opposite side thereof. All leads pass throughbushings 51 preferably of rubber which as illustrated in Fig. 2 arepreferably inserted and clamped between the cover 16 and the vupperedges of the portion 11 of the casing. the casing are preferablyarranged and connected as illustrated in Fig. 4 which connections iftraced will-be found to be the same as those shown in Fig. 6.

By referring to Fig. 3 it will be readily appreciated that the structureis so designed as to greatly facilitate assembly of the parts and toprovide convenient and expeditious access to all parts for inspectionand repairs, etc. The mere removal of the cover 16 gives ready access tothe whole interior of the device exposing the leads and theirconnections, the adjustable magnetic plug and its liding tubes andoperating means and in fact everything above the upper face of the frame5. It will further be observed that provision is made for thoroughventilation of the device notwithstanding the obvious compactnessthereof.

What I claim as new anddesire to secure by Letters Patent is asfollows 1. In a transformer, in combination, a support, a transformerframe carried thereby, transformer windingsmounted on said frame in aparallel relation, non-magnetic tubes interposed between said windingsto maintain the same in a spaced relation and magnetic plugs slidablymounted within said non-magnetic tubes.

2. In a transformer, in combination, a support, a transformer framecarried thereby, transformer windings mounted on. said frame in aparallel relation, non-magnetic tubes interposed between said windingsand magnetic plugs slidably mounted within said non-magnetic tubes andhaving means engaging said tubes to minimize the vibrations of saidplugs.

3. In a transformer in combination, a laminated transformer frame havingparal- The portions of the leads within,

lel openings on opposite sides of an intermediate portion, transformerwindings mounted on said intermediate portion of said frame in aparallel relation at opposite ends of said openings, rectangularnonmagnetic tubes inserted in the openings in said frame between saidwindings, magnetic plugs movable longitudinally in said tubes plugsadapted to be projected into said magnetic frame between said windings,said plugs being adjustably mounted in the upper box like member, saidupper member having a removable cover for giving access thereto.

5. In a transformer, the combination with two relatively inverted boxlike members of a horizontally disposed laminated magnetic frame clampedbetween said members, transformer windings mounted on said frame in aspaced and parallel relation and entirely inclosed by said frame andsaid members, vertically movable magnetic plugs adapted to be projectedinto said magnetic frame between said windings, said plugs beingadjustably mounted in the upper box like member, and said upper memberhaving a removable cover for giving access thereto,

, the incoming and outgoing leads for said windings all entering saidupper member and being accessible for connection and disconnection uponremoval of said cover.

In witness whereof, I have hereunto subscribed my name in the presenceof two witnesses.

THOMAS E. BARNUM.

Witnesses:

FRANK H. HUBBARD, G. W. HAYNES.

